Techniques have previously been proposed for the economic disposal of urban refuse by conversion to useful products intended for sale to offset the cost of collection and treatment. Treatment of refuse in such a manner to produce a refractory product through pyrolytic techniques has been disclosed in the prior art. Various of these techniques have involved the pretreatment of the refuse to provide separate fractions, the introduction of preheated oxygen-rich gas into a reactor either from the base or sidewalls, application of external heat to effect pyrolysis, and other expensive or inefficient techniques.
It should be understood that, for the purposes of this specification, except where the context clearly indicates otherwise, the term "pyrolysis" is to be comprehended as being used in a broad sense including the drying of refuse, the charring of incombustible organic material and the formation of inorganic oxides as well as the decomposition of organic material into volatile gases.
The term "solid waste material" as used herein, refers to the heterogenous mixture of organic wastes (including paper, food wastes, natural and synthetic rubbers, organic yard wastes, etc.) and inorganic wastes (including tin cans, glass, ceramics, etc.) conventionally obtained by urban refuse collection systems. It will be further described hereinafter.
Because of the low value of the refractory product obtained by prior act processes, such techniques have been of limited commercially feasibility and must operate at a very high level of efficiency. For example, the pyrolysis of the refuse should be closely controlled to insure that the organic components of the refuse are removed as volatiles so as to maximize both the purity of the refractory material being produced for sale and the percentage of the total available energy of the refuse being utilized by the system.
Existing pyrolysis reactors tend to be bulky in size to accommodate the large volumes of waste material to be processed and have elaborate mechanisms to seal the reactor during charging to preclude escape of the reactor gases. The size of these reactors and the need for elaborate sealing mechanisms obviously contribute to their high initial cost and high cost of operation.
Accordingly, it is an object of the present invention to provide a novel apparatus for disposing of solid waste material and obtaining substantially pure refractory material prills; as a product thereof.
It is also an object of the invention to provide such an apparatus which is highly economical as a result of the relatively low operating costs and high utilization of components.
It is another object to provide such an apparatus which enables close control of the pyrolytic treatment to obtain the maximum available energy from the refuse.
It is a further object to provide such an apparatus for producing valuable substantially pure ceramic prills of controllable size as a product of the waste disposal technique.
It is a final object to provide such an apparatus which is smaller than devices of comparable capability and which does not require elaborate sealing mechanisms.